Rapid and precise characterization of sub-µm surface defects using laser scatterometer devising a polygonal-shaped
Optics Express
|December 25, 2019
Summary
A novel laser scatterometer with a polygonal waveguide achieves over 10x improved defect detection efficiency. This system precisely quantifies sub-micrometer defect sizes and heights on flat surfaces.
Area of Science:
- Optical Engineering
- Metrology
- Surface Science
Background:
- Accurate detection of sub-micrometer defects on flat surfaces is crucial for quality control in various industries.
- Conventional laser scatterometers face limitations in detection efficiency and precision for micro-scale surface imperfections.
Purpose of the Study:
- To develop and validate a novel laser scatterometer for high-precision, efficient detection of surface defects.
- To enhance defect detection efficiency using an optimized polygonal-shaped waveguide.
Main Methods:
- A laser scatterometer system was designed utilizing a polygonal-shaped waveguide with a double-slit aperture.
- The system quantifies defect lateral size by pixel count and height by peak intensity.
- Performance was validated using a standard defective specimen and applied to glass panel inspection.
Main Results:
- The polygonal waveguide design improved detection efficiency by over 10 times compared to circular waveguides.
- Sub-micrometer lateral size and height of defects were accurately quantified.
- The system achieved high spatial resolution (31,250 × 16,000) for 250×140 mm² glass panels in under 10 seconds.
Conclusions:
- The proposed polygonal waveguide laser scatterometer offers a significant advancement in sub-micrometer defect detection.
- The system demonstrates high efficiency, precision, and speed suitable for industrial pilot production lines.
- This technology enables enhanced quality control for flat surface materials.
